A number of malt beverages or beers will produce a relatively good foam immediately after pouring, but the foams so produced are not as persistent as is usually desired by the consumers of such products. In addition, consumers desire a beer possessing a foam that will "cling" to the insides of a glass or mug in an attractive "lacy" pattern. Lace and cling are difficult to achieve in the presence of slight contaminant levels of surfactants or detergents on the glassware, as occurs when beer mugs or glasses are handwashed and quickly rinsed prior to use. A further requirement is that the beer exhibit good clarity to the consumer, i.e., the absence of any noticeable "haze".
Propylene glycol alginate (PGA), heteropolysaccharide S-10 (see U.S. Pat. No. 3,966,976) and cellulose ether (see U.S. Pat. No. 3,669,00) are additives known to stabilize beer foam.
However, continuing research is being conducted in an effort to discover new polymers, additives, and polymer combinations which may be more economical and which can be utilized to impart improved foam stability, lace and clarity to fermented malt beverages while avoiding attendant "haze" levels.
Xanthan gum as an extender or thickener in the food industry is well described in the literature. Also well known in the art is the use of collagen hydrolysates, derived from animal skin, in the preparation of hair care preparation, shampoos and skin care preparations. Collagen derivatives have been used in the brewing process as fining agents. Further, gelatin hydrolysates are well known in the pharmaceutical industry as tablet excipients used in granulating and binding operations during tablet manufacture. However, there are no general references to such compositions in combination being disclosed for specifically improving foam stability and properties of fermented malt beverages.